Process for the recovery of vanadium



i I Patented Aug. 17, 1926. p

UNITED STATES PATENT OFFICE.

FREDERICK F. ERICK, OF ANACONDA, MONTANA, ASSIGNOR TO ANACONDA COPPER MINING COMPANY, OF ANACONDA, MONTANA.

PROCESS FOR THE RECOVERY OF VANADIUM.

No Drawing. Application filed October 16, 1925. Serial No. 62,889

This invention relates to a process for the giving a loose pulverulent mass containing 5 recovery of vanadium, an object of the m to percent of $0,. This mass is mixed vention being to obtain a good yield of the with 7 5 to 100 percent of its weight of soda vanadium in a commercially pure form suitash and the mixture fused at a bright red 5 able for use, for instance, in the manufacture heat. The melt is then granulated in water of ferrovanadium from materials containing and leached. The products of the leaching vanadium and impurities such as arsenic and operation are a residue containing practiphosphorus. cally all of the iron content of the starting The process, although applicable for the material and a solution containing the 10 recovery of vanadium from vanadium-con vanadium in the form of sodium vanadate taining materials in general, has been deand also arsenic, phosphorus, alkali metals, veloped particularly in connection wlth the alkaline earth metals and sulfates. The sorecovery of the vanadium ,content of solution is acidified to about 10 grams of free, called burned sawdust residues produced by sulfuric acid per liter and boiled with the ,the treatment of hosphate rock described addition of a small amount of an oxidizing in United States atent No. 1,544,911. In agent, preferably potassium 'chlorate, in the process of thatpatent phosphate rock quantity equal to 5 to 15 percent of the is leached with sulfuric acid, the resulting weight of the vanadium in the solution. solution is treated with a soluble ferrocy- This treatment results in the precipitation 20 anide to precipitate the vanadium and the of about 95 percent of the vanadium conprecipitate is treated with an alkali to retent of the solution as the red vanadium 7 generate the soluble ferrocyanide forre-use, pentoxid. The phosphorus andarsenic conleaving a residue rich inevanadium but contents of the solution are not precipitated. taining also objectionable quantities of im- The precipitated vanadium pentoxid is sepapurities. A typical analysis of this residue rated from the reaction mixture and washed which has been referred to as burned sawwith a dilute sulfuric acid solution containdust residue is 6 to 10 percent of V and ing about 5 grams of sulfuric acid per liter. about 20 percent of Fe- O 28 percent of The washed precipitate contains about CaO, 4 percent of Nap, 5 percent MgO, to percent of the vanadium content of v 1 percent of-lP O and 0.1 percent of AS203. the Starting material and is substantiallv The process will be described and illusfree of phosphorus and arsenic, being sufli- 85 trated in connection with the treatment of ciently pure in this respect ,to permit its use this material or residue. The residue is for the preparation of high grade ferroboiled with-a sufficient quantity of dilute vanadium alloys. I sulfuric acid solution, about 20 percent, to In the foregoing description I have given give a solution containing about 20 grams of what I now regard as the best method of 00 vanadium per liter and an extraction of treating a vanadium containing material'of about 99 percent of the vanadium content of the character of the burned sawdust residue, the residue. The resulting solution is sepa- I but I appreciate that many changes and 40 rated from insoluble matter which contains variations of the method may be made, either i I the bulk of the calcium content of the resito better adapt it to the treatment of a dif- 95 due as calcium sulfate. The separated soferent starting material or merely to suit lution contains vanadium sulfate besides the convenience or personal preference of 1I'OI1, phosphorus and arsenic compounds and the operator, Withoutdeparting from the l5 other impurities which must be separated. principles of the-invention which-are gen- The, solution is reduced to dryness, prefererally as followsi The first step is to get the 1 ably by mixing it with a suflicient quantity vanadium with such impurities as may acof the dry product of a previous operation, company it into a sulfate solution, thus so'that the mixture may be evaporated witheliminating the bulk of'the calcium content out crusting or sticking to the hot surfaces of the starting material. The second step is of the evaporating apparatus. The resultto evaporate the sulphate solution and ignite 1 ing dry'material is then calcined at a dull it to' partly decompose the sulphates. The red heat, as a result of which the iron and third step is to fuse the ignited residue from vanadium sulfates are partially decomposed, the preceding step with an alkali or alkaline m carbonate in order to rehder the vanadium soluble and the iron insoluble in water. The

tion. Any process involving these principal steps or variations thereof or substitutes therefor or the addition or elimination of a step or steps in case it is possible or convenient in the treatment of a particular material, may be regarded as falling within the scope of my invention. I claim lqProcess for the recovery of vanadium which comprises leaching a crude vanadiumcontaining material with sulfuric acid, reducing the resulting solution to dryness, fusing the dry residue with soda ash, extracting the fusion with water, acidifying the extract, adding a chlorate to the acidified extract, and boiling the mixture.

2. Process for the recovery of vanadium which comprises extracting a material containing vanadium, calcium, iron, phosphorus and arsenic compounds with "sulfuric acid, separating the resulting solution from insoluble matter, adding to the solution the solid residue produced by evaporating a similar solution to dryness, reducing the mixture to dryness, fusing the dry mixture with soda ash, extracting the fusion with water, acidifying the solution, and boiling the acidified solution with the addition of an oxidizing agent.

3. Process of recoverin vanadium which comprises mixing an aci extract of a vanadium-containing material with the dry residue of a similar solution from a previous operation, and reducing the mixture to dryness.

In testimony whereof, I aflix my signa- 

